Magnetism， magetostriction， and M?ssbauer effect studies of Tb0.3Dy0.6Pr0.1(Fe1-xAlx)1.95 alloys

The effects of Al substitution for Fe on the structure the magnetism the magnetostriction the anisotropy and the spin reorientation of a series of Tb0.3Dy0.6Pr0.1Fe1-xAlx1.95 alloys x=0.050.10.150.20.250.3 at room temperature are investigated. It is found that the compositions of Tb0.3Dy0.6Pr0.1Fe1-xAlx1.95 substantially retain MgCu2-type C-15 cubic Laves phase structure when xx=0.2 and the mixture phase increases with x increasing. The lattice constants increase linearly Curie temperature decreases gradually and the coercive force decreases sharply with x increasing. The vibrating sample magnetormeter measurements show that the relationship between magnetization and substitution x is rather ambiguous. The magnetostriction of the Tb0.3Dy0.6Pr0.1Fe1-xAlx1.95 alloys decreases drastically with x increasing and the magnetostrictive effect disappears when x>0.15. However a small amount of Al substitution is beneficial to a decrease in magnetocrystalline anisotropy. The analysis of the Mssbauer spectra indicates that the easy magnetization direction in the {110} plane deviates slightly from the main axis of symmetry with the increase of Al concentration xnamely spin reorientation takes place, thereby leading to the change of macroscopical magnetism and magetostriction.